HI so i have photoshop lightroom and it chrashes all the time, but the worst problem is that i can¨'t import and i have enough space on my computer, it just says importing photos forever and i have tried to uninstalling it and install it again with no result.

Sounds more like you have a hardware problem. I have LR installed on 2 different systems, both Windows 7 SP2, and it never crashes. But then I know for a fact I don't have any hardware problems with either system. One notebook and my main desktop. In fact I have the desktop overclocked by 1+Ghz's and never had a crash of any program.